Rather than mess up a "I'm having fun drag racing" type thread, I thought I'd summarize a few things that seem to work for me this year.
Swapping to 26x
10x15 MT ET drag slicks. Although I was able to get the old 26x
9x15 QTP Hoosier DOT's and the 26x
8.5x15 MT drag slicks to get into the 1.6x 60' range with my old combination, my new combination was too much for the skinny tires. The new 26x
10x15 MT ET drag slicks are certainly an improvement. Now when I do a burnout, I can see when the RPM's drop on the tach, which is when they start to bite. With the old tires, that never seemed to happen.
When I installed these slicks, I did it tubeless, but with rim screws. As advised, I used the most commonly recommended tip and smeared about 1/2 a bottle of regular Dawn dish soap in each, particularly the side walls, and left them soak for an hour before wiping up the excess and then mounting to the rim. I used bolt-in steel valve stems which seem to work just fine. So far, after about 20 runs, the tires still hold air well a week later after some runs. It has been recommended to me that next time I should use a 26x10x15
S with my stick car which has a different compound and stiffer sidewalls than the base ET slick that I have.
The 26x10x15's fit my car great with the 8" wide, 4" backspace Magnum 500 wheels. Most cars would probably have a problem with this combination (due to the 4" backspacing), but my car had the quarters pushed out and the beads rolled back in 1978 when I did the bodywork. Thank god for some foresight on my part.
An ultimate tire choice for me would probably be a 28x9x15 as they give a larger footprint. Unfortunately not all 65/66's can hold them without wheel well and/or spring perch modifications. I was concerned about tire growth at the upper end of the track and don't want to chance doing high speed donuts at 120mph. I still might go there in the future, but will do what takes in order to make it safe--which could entail more body work.
Calvert shocks--They are non-adjustable. Definitely allows the front of the car to rise faster than the Summit/CE's. This weekend's track observers said that most times the front end would drop back down just before the next gear shift which would cause the front to fully rise again. The 1/8 mile observer also said that each time I am shifting into 4th, the rear of my car jumps to the right so I definitely need the weight transfer even down the track.
I do need to measure the actual front end lift lift, as I might need to do some limiting. Calvert recommends 4-5.5" of lift and the car always looks like it is going to leap down the track during launch and subsequent gear shifts:
2-step and line loc--The 2-step give me a consistent, predetermined launch RPM and allows for a normal upper RPM rev limiter. The line loc is needed for burnouts with my stick car.
Last year I ran both, but independently of each other. When I staged, I normally just broke the beams and tried to stay there, even though our staging area has more waves than the Atlantic boardwalk.
Sometimes you drift, sometimes you don't. This year that helped cost me a class win in my first race of the season.
Now I have the ability to either run the line loc just for burnouts, or set both the 2-step and the line loc at the line with just the flip of a momentary toggle switch.
I keep the toggle switch in one position to allow the shifter mounted switch to handle the burnout. Once staged, I lightly hold the brakes and move the toggle to the "arm" position and it activates both the 2-step and the line loc simultaneously. From then on, all I need to do is let the clutch out (which releases both features) and then race down the track. Neither the lower RPM constraint, nor the line lock activate as I am going through the gears. This feature should prove very valuable in future races.
Sintered Iron clutch with adjustable pressure plate--The sintered iron clutch setup is expensive and not recommended unless you have true drag ambitions or your car is to powerful for a standard clutch. It is streetable, but requires a little experience to master in that capacity. Sometimes it gives a little metallic sound that sounds like you are spinning the tires, even though you are not. It works great for power adder cars that blow away a standard clutch. Its adjustable features give you more tuneability at the track that can help a poorly launching car get off the line.
I find that the adjustable pressure plate has a light pedal, but still not as quite as light as the Centerforce DF or the Spec diaphram clutches I used last year. One thing cool about this clutch is that it is the "Long" style and this style of clutch is know to allow smoother shifting at high RPM's. I now have no grind like I did last year (in any of my 6400rpm gear changes) and have yet to miss a single speed shift in nearly 25 track runs.
There are things with this clutch that I am still trying to figure out, and things that I discovered too late. You have an option of either buying a counter weighted adjustable pressure plate, or an not-counter weighted version--by all means purchase the counter weighted one, even if you don't know anything about it or don't plan on using it.
I bought the wrong one and it is hindering me at the track as I can now utilize the light static pressures at launch, but because I cannot use counterweights, I cannot get the clutch to lockup in the higher gear. I will need to send my PP back to Ram and have them modify it in the near future--extra $$ as it will be considered a rebuild since I have been running the clutch, as is.
Luckily, when I dial in more static pressure, the clutch will hold just fine in all gears even though I don't get all the advantage of this type of clutch. If the flywheel is properly marked, it takes approximately 10-15 minutes to make an adjustment. A helper who can turn the crankshaft is a plus and can lessen that time considerably.
One thing that I have noticed with this clutch that may make the added cost of these clutches worth it (besides the smoother gear changes) is that they do not hit as hard in each gear as other fixed pressure clutches hit--mainly the Centerforce dual friction and the Spec 2+ daiphragm clutches that I tried last year. Softer hits allow the tranny and the rearend to survive much longer when using drag tires. Softer hits also eliminate most of the bog that normally occurs as each gear is engaged and that translates into better ET's and higher MPH because the motor stays well into it powerband.
For a mostly street clutch, I still think that the Centerforce DF is da bomb. When the car eventually gets retired back to strictly street duty, that clutch is going back in. It had a very light pedal and never faltered at the strip, even when hotlapping. The Spec 2+ also had a similar feel, but it did give me some slippage last year on hot days. Even so, I had my best times of the season at the end of the year using this clutch.
Let me know if you find any of this info useful, or if I would be better off spending my time changing the air in last years slicks. I think that that the air might be getting stale and thus heavier after a years use.
Today
